by the frequency with which he refers to the subject. With the object of procuring further information he sent his "notice" to Russia, and from Baron von Asch, surgeon in the Russian army, he learned that in January, February, and March, 1782, a disease described as "febris catarrhalis epidemica benigna" prevailed in the Russian capital. It originated in eastern Siberia, on the Chinese frontier, and spread through the whole of Russia. -The British Medical Journal.

SCIENTIFIC BOOKS

A Text-book of Precious Stones. By FRANK B. WADE, B.S. Published by G. P. Putnam's Sons, 1918. 8vo, pp. xiii + 318. Illustrated.

Those who are familiar with the work on "Diamonds" by the same author will find the present book characterized by similarly attractive features. The style is clear and precise and readability and practicality are afforded by examples drawn from the writer's own experience.

The book will appeal to the amateur rather than the professional student, but this is probably the intention of the author. His experience as a teacher has doubtless aided him in presenting the subject in a systematic and easily assimilable manner. The physical properties of gems are treated under the various subdivisions of refraction, absorption and dichroism, specific gravity, luster, hardness, and color, each to the extent of one or more chapters, and numerous practical details are given in the chapters on testing, cutting, occurrence and imitation of gems. The chapter on "tariff laws" affords useful information not readily found elsewhere and the bibliography of the subject of gems is the most complete and satisfactory for the purposes of the general reader that the reviewer remembers to have seen. The book is not extensively illustrated, a few text figures from line drawings comprising all the pictures that are provided.

Besides its usefulness for general reading, the title of the book and its systematic plan suggest that it could be employed for more formal instruction. The wide distribution of

gems in Nature and their possession in some form in almost every home, make it probable that they could be used more extensively than is now the case as a basis for school study.

The reviewer finds little to criticize adversely in the book beyond the occasional use of the term "gemology." While this term might be generally understood to refer to the science of of gems, it is incorrectly formed for this purpose and in reality has quite a different meaning. The Greeks seem to have had no single term for distinguishing objects used for the purposes for which we use gems, but indicated things of value by the adjective Tivos. Prefixing this adjective to Xídos, stone, the term tiniolithology can be obtained, which is at least a word properly formed to indicate the science of gems.

OLIVER C. FARRINGTON FIELD MUSEUM OF NATURAL HISTORY

SPECIAL ARTICLES

PINK ROOT OF ONIONS

IN 1915 Professor F. W. Mally called the writer's attention to a very serious disease of onions in Webb County, Texas, and locally known as pink root. Investigations were begun on this disease with Professor Mally, who cooperated in the field experiments and offered valuable assistance in many ways. A search in literature showed that there were no records that could be found, where mention was made of this new plant trouble. From conversation with Professor Mally I was told that Professor W. M. Gilbert, of the United States Department of Agriculture, had at one time worked on this disease and also published an account of the same. However, a letter received from Professor Gilbert dated May 15, 1918, says as follows: "So far as I know there are no publications on this disease, as I did not do enough work on it to secure results for publication and have not had the opportunity to study it very recently." The writer was the first to report on this disease in 1917.1

1 Taubenhaus, J. J., "Pink Root, a New Disease of Onions in Texas," Phytopath. 7: 59, 1917 (abstract).

The symptoms of this trouble are very striking. Affected roots turn yellowish, then pink and dry up. The disease is confined to the roots only and not to the bulb. As fast as the old roots are affected new ones are produced, these in turn becoming diseased. In the end, the bulb spends all its energies in producing new roots which in turn become affected, thus failing to attain the commercial standard. Diseased bulbs remain dwarfed and small to the end of the season, although apparently sound in every other way. The average annual loss from this disease in Webb County may be estimated at forty per cent.

Careful investigations in the laboratory of the Texas Experiment Station revealed the fact that the disease was caused by an apparently new pathogenic organism, the name of which is proposed to be Fusarium malli, n. sp. Over one thousand plate cultures were made from diseased material and in nearly every case a pure culture of the above organism was obtained. Moreover in planting healthy onion sets in both sterilized sand or soil in which a pure culture of the Fusarium fungus was worked in, the disease in each case could readily be reproduced. The symptoms on the artificially infected plants were in every respect identical with those of infected plants naturally found in the field. The checks remained free, proving that Fusarium malli Taub. is the cause of pink root.

Numerous laboratory experiments, which were duplicated in the field have yielded results which are briefly summarized as follows:

1. The disease is carried with infected sets. 2. The disease is carried over from year to year in the soil. Short term rotations with other crops than onions on pink root lands do not starve out the pink root fungus.

3. Pink root attacks not only the onions but also the garlic and the shallot. It does not seem to attack any other of the liliaceous plants.

4 Steam sterilizing will kill the fungus in the soil. Formaldehyde at the rate of one pint to twenty gallons of water, per square

foot will also rid the soil of the causal organism.

5. Applications of lime will not rid the soil from pink root.

6. In infected soils liberally fertilized, especially where quickly available plant food is applied, together with proper cultural management, the crop can be nursed to produce fairly normal yields. In this case the proper fertilizer merely stimulates the bulbs in producing new roots faster than the disease can destroy them.

7. Fertilizers rich in nitrogen and organic matter are especially valuable for use in soils infected with the pink root.

8. Healthy sets when planted on diseased soils will contract the disease. Likewise, diseased sets planted on healthy soils will also yield diseased bulbs.

Numerous experiments both in the field and in the laboratory are still in progress and as soon as these are completed a bulletin will be published by the Texas Experiment Station giving a full description of the causal organism and results of the experiments. J. J. TAUBENHAUS

COLLEGE STATION, TEXAS

A CHROMOSOME DIFFERENCE BETWEEN THE SEXES OF SPHÆROCARPOS TEXANUS

THE chromosome group in the cells of the female gametophyte of Sphærocarpos texanus is characterized by one large element greater in length and in thickness than any of the other chromosomes in the group. This large element does not appear in the chromosome group of the male gametophyte, but instead there is a small chromosome commonly nearly spherical in form, and unlike anything found in the female. The other chromosomes in the cells of both sexes vary in length. They have the form of rods, usually curved. The chromosome number for each sex seems to be eight. In the cells of the female, seven of the eight are similar respectively to seven of the male. The eighth chromosome of the female (the largest one) seems to correspond to the small chromosome of the male. The condition as to the chromosomes of the gametophytes in

In the absence of the vice-president, Dr. H. P. Armsby, who is with the Interallied Food Commission in Europe, Dr. A. F. Woods presided over the session. This was devoted to the agricultural situation in Europe as viewed by members of the American Agricultural Commission which spent several months in Great Britain, France and Italy in the early fall.

Describing "Some Impressions of the Effect of War on Agriculture in England and France," Dr. W. A. Taylor reviewed the highly successful efforts in England to stimulate production resulting in 1918 in an increased area in cereals of 32 per cent. and in potatoes of 45 per cent. over the ten-year prewar average. This increase was not due to the existence of an actual shortage, for ap

parently at no time was there less than three months supply of wheat in sight, or to the expectation of large profits on the part of farmers, but rather to apprehension that conditions might grow worse and to the necessity of saving tonnage. The organization through which the increase was accomplished and the measures put in force under the Defense of the Realm Act were effective and often revolutionary. Local production campaigns were in the hands of agricultural executive com

1 Allen, C. E., "A Chromosome Difference Correlated with Sex Differences in Sphærocarpos, SciENCE, N. S., 46: 466-467, 1917.

failed to take drastic action, even to dispossessing tenants and breaking up and operating idle land at the expense of the owners. Restrictions on the crops to be grown, their sale and use were extensive and far exceeded anything hinted at in this country. A reform of much importance was the putting into operation of a seed control measure similar to that maintained in several of the states in this country, which yielded such beneficial results that it is expected to be permanent. The government also controlled the price of certain seeds, as seed potatoes, and to avoid local shortages purchased nearly a million dollars' worth of seed potatoes for sale to commercial growers and allotment holders.

While tenant farmers profited by good prices and reduced competition, land owners were prevented by law from raising their rents during the war despite increased taxes and other expenses. In consequence the sales of land exceed those for a generation, and include not only large holdings but relatively small farms, mostly land not operated by the owners. Purchasers are mainly of the tenant farmer class, and no marked movement of population from the city to the land was noted. There was much evidence of greatly aroused interest in agricultural research, instruction and extension teaching which is expected to bear fruit in increased facilities.

In sharp contrast to Great Britain, France showed abundant evidence of decreased crop production, as was to be expected. In 1917

the production of cereals fell to 53 per cent. of the pre-war average. A return to nearly 75 per cent. in 1918 was "accomplished through most strenuous and exhausting effort and to a considerable extent at the expense of future crops through the breaking up of the best crop rotation practise."

The reconstruction problems in France were described as complicated, one of the most difficult being the remanning of the land. Of the 250,000 farmers of the devastated region it is estimated that perhaps 100,000 may return to their holdings. Much of the land consists of small parcels, the holdings of an

owner being more or less scattered, which points to the importance of consolidating these tracts into compact units capable of more economic management. The question of whether the destroyed rural villages should be rebuilt on their old sites rather than to relocate them more advantageously is another matter of considerable importance. A rapidly growing sentiment was noted for the restoration of the devastated region by the invaders, rather than the mere payment of financial indemnity. The French government has already provided a credit of approximately sixty million dollars, from which allowances are being made to farmers who are ready to return to their land. For the most part the restoration of the fields did not impress the commission as being as appalling as might be expected, and was compared with the reclamation of stump land in this country.

Speaking of the Live Stock Conditions in Europe, Mr. George M. Rommel reported that European farmers had been quite successful

in maintaining their supplies of breeding animals. Although they have suffered from a shortage of feed and some inroads have been made on certain kinds of stock by the military demands, the number of cows and heifers in Great Britain is fully as large now as before the war, and this is true of cattle generally. The milk supply has been reduced on account of the shortage of concentrated feed, and this has also cut down the number of pigs quite extensively. There was also a small falling off in sheep.

In France there are about two million less cattle than before the war, principally due to invasion. Since the close of 1914 the decline in number of cattle has been less than 2 per cent., the young stock having increased. A similar increase also applies to Italy. Sheep have declined nearly 40 per cent., due largely to labor shortage, and hogs somewhat more due to a lack of concentrated feed. The shortage of milk in France is more serious than in Great Britain. The heavy demand for horses for military purposes has reduced the available number by about a million. The record of the Percheron horses in the British

army has excited a good deal of interest among farmers and breeders in England and led to efforts to establish this breed of horses in that country.

Prices of breeding stock were reported as extremely high in both France and England. Breeders are anticipating a good trade after the war and have kept their stocks intact at great expense. Not much demand for live stock from the United States was looked for in the immediate future, although dairy cows may be needed and after the war American horses will doubtless be required in Europe, mainly of the commercial grades.

Mr. E. C. Chilcott, who went to the French colonies at the instance of the French High Commission, was to have described the agricultural conditions found there, especially in Algeria, but was detained by illness.

At the business meeting Dr. A. F. Woods, president of the Maryland Agricultural College, was nominated vice-president, and Dr. J. G. Lipman, director of the New Jersey Experiment Stations, secretary of the section, and these nominations were subsequently confirmed by the general committee of the association. Other officers for the year were elected as follows: Member of the general committee of the association, Mr. George M. Rommel, U. S. Department of Agriculture; member of the council of the association, Dr. A. C. True, U. S. Department of Agriculture; member of the sectional committee (for five years), Professor C. P. Gillette, director of the Colorado Experiment Station.

in the City of New York

Session begins in September

Candidates for admission must be graduates of approved colleges or scientific schools with at least one year's instruction, including laboratory work, in physics, chemistry, and biology, and with evidence of a reading knowledge of French and German.

Each class is limited to 90 students, men and women being admitted on the same terms. Except in unusual circumstances, applications for admission will not be considered after July 1st. If vacancies occur, students from other institutions desiring advanced standing may be admitted to the second or third year, provided they fulfill all of our requirements and present exceptional qualifications.

INSTRUCTION

The next academic year begins September 30, 1919 and aloses on the second Tuesday in June. The course of instruction occupies four years, and especial emphasis is laid upon practical work in the laboratories, in the wards of the Hospital and in the Dispensary.

TUITION

The charge for tuition is $250 per annum, payable in three instalments. There are no extra fees except for rental of microscope, certain expensive supplies, and laboratory breakage.

The annual announcement, application blanks, and circular describing graduate courses may be obtained by addressing the Dean of the Johns Hopkins Medical School Washington and Monument St.

School of Medicine

REQUIREMENTS FOR ADMISSION Candidates for entrance are required to have completed at least two full years of college work which must include English, German, and instruction with laboratory work in Physics, Chemistry and Biology.

INSTRUCTION

Instruction begins on the last Thursday in September and ends on the second Thursday in June. Clinical instruction is given in the Barnes Hospital and the St. Louis Children's Hos pital, affiliated with the medical school, the St. Louis City Ho pital, and in the Washington University Dispensary.

COURSES LEADING TO ACADEMIC
DEGREES

Students who have taken their premedical work in Washington University, are eligible for the degree of B.S. upon the completion of the first two years of medical work.

Students in Washington University may pursue study in the fundamental medical sciences leading to the degree of A.M. and Ph.D.

TUITION

The tuition fee for undergraduate medical students is $300 per annum. Women are admitted.

The catalogue of the Medical School and other information may be obtained by application to the Dean.

Euclid Avenue and Kingshighway St. Louis

Tulane University of Louisiana

COLLEGE OF MEDICINE

(Established in 1834)

School of Medicine

After January 1 1918, all students entering the Freshman Class will be required to present credits for two years of college work, which must include Biology, Chemistry and Physics, with their laboratories, and one year in German or French. Graduate School of Medicine

A school for physicians desiring practical clinical opportunities, review, laboratory technic or cadaveric work in surgery or gynecology. Excellent facilities offered in all special branches. School of Pharmacy—

Admission: Three years of high school work, or 12 units. Two years for Ph.G. degree. Three years for Ph.C. degree.

School of Dentistry

Admission: Four years of high school work, with 15 units. Thorough, practical, as well as comprehensive technical training in dentistry.

Women admitted to all Schools on the same terms

as men.

P. O. Box 770, New Orleans, La.